Coronary Artery Disease, Diabetes, and Dementia: What’s the Relationship?

Comorbid coronary artery disease (CAD) and diabetes are associated with an increased risk for dementia, according to study findings published in the European Journal of Preventative Cardiology.

Diabetes is associated with increased risk for cardiovascular diseases and those with comorbid CAD are at increased risk for myocardial infarction and cerebrovascular events.

Researchers from Aarhus University in Denmark hypothesized that patients with comorbid diabetes and CAD could also be at increased risk for dementia. The researchers sourced data for this study from nationwide registers in Denmark. Individuals (N=103,859) aged 65 and older who underwent coronary angiography between 2003 and 2021 were evaluated for dementia through 2022 on the basis of diabetes and CAD statuses.

“ [T]he risk of dementia associated with diabetes is partly mediated through the presence of atherosclerotic CVD, which underscores the importance of atherosclerotic CVD prevention in diabetic patients to reduce the risk of cognitive decline.

The study cohort comprised patients with:

neither diabetes nor CAD (n=23,189; mean age, 75; men, 43.8%; body mass index [BMI], 26 kg/m 2 ),

), diabetes (n=3876; mean age, 75; men, 47.4%; BMI, 29 kg/m 2 ),

), CAD (n=61,020; mean age, 74; men 66.2%; BMI, 26 kg/m 2 ), or

), or both diabetes and CAD (n=15,774; mean age, 73; men, 68.2%; BMI, 28 kg/m2).

The events per 1000 person-years for each group were as follows:

Control group:

all-cause dementia, 8.0

Alzheimer dementia, 3.8

vascular dementia, 1.6

stroke, 6.1

Diabetes group:

all-cause dementia, 8.0

Alzheimer dementia, 3.7

vascular dementia, 1.7

stroke, 9.2

CAD group:

all-cause dementia, 9.3

Alzheimer dementia, 4.2

vascular dementia, 2.2

stroke, 7.9

Comorbid diabetes and CAD group:

all-cause dementia, 10.0

Alzheimer dementia, 4.5

vascular dementia, 3.2

stroke, 13.1

Compared with control individuals, all-cause dementia was associated with CAD (adjusted hazard ratio [aHR], 1.11; 95% CI, 1.03-1.20) and comorbid diabetes and CAD (aHR, 1.37; 95% CI, 1.24-1.51).

Alzheimer dementia was associated with comorbid diabetes and CAD (aHR, 1.41; 95% CI, 1.23-1.62). Vascular dementia was associated with CAD (aHR, 1.28; 95% CI, 1.10-1.49) and comorbid diabetes and CAD (aHR, 2.03; 95% CI, 1.69-2.45).

Meanwhile, stroke was associated with diabetes (aHR, 1.46; 95% CI, 1.25-1.70), CAD (aHR, 1.27; 95% CI, 1.18-1.37) and comorbid diabetes and CAD (aHR, 1.87; 95% CI, 1.70-2.06).

Among patients with comorbid diabetes and CAD, all-cause dementia (aHR, 1.34; 95% CI, 1.08-1.66) and Alzheimer dementia (aHR, 1.39; 95% CI, 1.01-1.91) were associated with diffuse vessel disease. However, vascular dementia was associated with 1 vessel (aHR, 2.07; 95% CI, 1.41-3.02), 3 vessel (aHR, 1.79; 95% CI, 1.20-2.66), and diffuse vessel (aHR, 2.04; 95% CI, 1.34-3.10) diseases relative to diabetes without CAD.

Diabetes duration, insulin use, and gender were also predictors for all-cause dementia among patients with comorbid diabetes and CAD. Regardless of CAD status, patients with diabetes who had glycated hemoglobin above the 75th percentile were at increased risk for all-cause dementia. Patients with type 1 diabetes were at lower risk for all-cause dementia than those with type 2 diabetes (aHR, 0.73; 95% CI, 0.56-0.96).

The major limitation of this study is that dementia is substantially underdiagnosed, so some cases may have been missed in this study.

“Our results suggest that the risk of dementia associated with diabetes is partly mediated through the presence of atherosclerotic CVD, which underscores the importance of atherosclerotic CVD prevention in diabetic patients to reduce the risk of cognitive decline,” the researchers concluded.

Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.